THE MALDIVES 391 



surrounding them like ghosts of an atoll, and enclose a 

 lagoon, light blue or emerald-colored, according to its 

 depth. These faros are not necessarily circular ; they 

 vary greatly and are indirectly controlled by the topo- 

 graphy of the bottom. When nearly circular, there have 

 probably been no agencies to interfere with the symmet- 

 rical growth of the coral. Some of the inner faros are 

 elliptical, pear-shaped, or crescent-shaped, but as a rule 

 they are much more symmetrical than the faros of the 

 outer rim, which are distorted by the full force of the 

 monsoons. 



The ring-like faros are apparently formed by the up- 

 ward growth of circular or elliptical patches of corals 

 occupying slight elevations above the general level of 

 the surrounding plateau. These patches may grow up 

 uniformly to form a bank, or they may grow up as rings, 

 the corals of the outer face only rising toward the sur- 

 face, those in the centre being killed by want of clean 

 water and food, or choked with sand that is washed into 

 the interior, which is filled more slowly than the growth 

 of corals on the rim. When the rim reaches the surface 

 it may develop in two ways. In one case, the lagoon 

 may gradually fill in and be changed into a flat with an 

 islet or islets forming on its rim ; these may slowly grow 

 to cover the whole reef flat. The islets become covered 

 with scant vegetation from the adjacent faros ; with the 

 growth of the land, large trees will obtain a foothold, 

 till at last what was once a submerged faro will be trans- 

 formed into a densely wooded island. In the other case, 

 a sand bar may form a little islet or islets on the rim of 

 the lagoon ; these islets are gradually joined together 

 and become crescent-shaped, the horns throw out spits 

 (much as the horn forming Provincetown Harbor has 



